Chucking mechanism



Sept. 25, 1951 A. E. DRISSNER 2,569,093

cuucxmc MECHANISM Filed May 4, 1948 3 Sheets-Sheet 1 IN V EN TOR.

WM BY%M 72 W Sept. 25, 1951 Filed May 4, 1948 A. E. DRISSNER CHUCKINGMECHANISM 3 Sheets-Sheet 2 INVENTOR.

Z6175, BY

p 1951 A. E. DRISSNER CHUCKING MECHANISM 3 Sheets-Sheet 3 Filed May 4,1948 Patented Sept. 25, 1951 cHUcKmc MECHANISM Alfred E. Drissner,Cleveland, Ohio, assignor to The National 'Acm'e' Company a rcorporation of Application May 4, 1948, Serial N0 25 033 My inventionrelates in general to an improved chucking mechanism which will rotatethe workpiece so that both ends may be machined simultaneously.

This application is a continuationin part of my former applicationentitled, Valve Stem Chucking Mechanism which was filed July -2l, 1944,and bears Serial No. 5 l6,i)39, now abandoned. As was stated in theoriginal application, a gripping pressure of approximately 2800 poundsmust be exerted upon each end of a valve stem by the chucking mechanismwhich rotated the valve for machining.

I have discovered that my improved chucking mechanism will grip thevalve stem so that both ends thereof may be machined simultaneously. Oneof the major problems which had to be solved in designing, thevalvechucking mechanism was to provide a driven gear containing the chuckingmechanism small enough so that both ends of the valve would stick out ofthe driven gear. Another problem which had to be solved was the timerequired for chucking the valve stem.

Therefore, an object of my invention is to providea driven gear withavalve chuckingmechamsmsmn enough so'that bot'hiends of the valve stickout of the driven gear for simultaneous machining of both ends.

Another object'of'my invention is to proyide a'chucking mechanismwhich"will'igrip both ends of the valve stem'with equal'grippingpressures.

Anotherobjec't' of my invenutrf'is to provide a driven'gear with achucking mechanism which may be operated to chuck the workpiece whilethe'driven gear and chucking mechanism-are rotating.

Another object of my invention is to provide a chucking mechanism with"chucking collets which are restrained against axial movement and whichare moved radially to grip -the workpiece.

Another object of my invention is to" provide a chucking mechanism witha pair of collets'and means to regulatethe distance between thesec'ollets, thus regulating the gripping diameter ofeachcoll-et. f

Other objects and a fuller understanding of my invention may be had byreferring tothef following description and claims, taken" in con'j'un'ction with the accompanyingdrawingsjin which: Figure lis a cross sectionofa single spindle machine illustrating a driven gear'having avalvestemchuck therein with tools shown 'inphantom machining both BIldS Qf:the valve, Figurel2' is an enlarged cross-sectianal view 7 Claims. (01.279-56) of the driven gear illustrating the chucking mechanism'in openpositio'n'w'ith a valve inserted l .l l,

1' Figure 3 is a fragmentary enlargement of the driven gear illustratingthe valve gripped by the chucking'meclianismf Figure 4"isav'ie'w takenalong the lines 4-4 of Figure 3; and

' Figure 5 Ba view taken along the lines 5-5 of Figure 3. e

In my description and claims I refer to the manufacturingof valves."However, it is under stood that my machine ma'yeasily befuse'd tomachine both ends'of any rotatable workpiece, such'for example as axles;andthatiby"thus' referring to the 'manufacturingof valves '1 do notlimit the scope of my invention to valves.

In Figure '1, I illustratamy improved chucking mechanism as beingincorporated in'. a'dr'iven gear I l which is. carried by. 'a"supportingstructure 'lj0 and rotated by deriving gear; Several'driven gears I l'mayfbe' supported about 'the ported so that'it' is always in meshwith,the

end of the stem l8 ofith'e'valvie l6.

driving gear l2 and between tools" l4ifand [5 which are shown inphantom. The tool [4' is positioned to machine the'headll of thevalveI6, and the'tool l5is positionedrto, machine the The driven gear I Icarries th'e chucking mechanism which rotates the valve Hi. "The drivengear H as illustrated inFigures' 1 and "2 has a length less'tha'n'thelength of the 'valvesterh,

and may be "referred'to" as a housing for my chucking'mechanism Thishousing has'a bearing portion 20 onone e'ndfthereo'f and a bearingportion 2! on the other end thereof, with gear teeth 22disposedjtherebetween'and extend"- ing radially from the housing to meshwith" the teeth 'of' the 'driving "gear l2. A- roller bearing race 23encircles the bearing p ortion.20'.and bear ingly supports it in thesupportingstructure lll. Similarly; a; roller bearing race '24 encirclesthe bearing portion 21 and bearingly supportshit in the supportingstructure [0, with the. gear teeth 22 disposed between theirollerbearing'races 23 and 24. In my drawings I have -illustratedfthe gearteeth 22, andthus the .drivengear L], as

3 having a diameter smaller than the diameter of the roller bearingraces 23 or 24. Plates 25 are fastened to each'side of the supportingstructure ID by bolts 26. These plates 25 abut the roller bearing races23 and 24 and hold them in correct spaced position in the supportingstructure to prevent axial movement of the driven gear relative to thedriving gear.

A cap 21 is threaded into the bearing portion 20 of the housing ordriven gear I and a cap 28 is threaded into the bearing portion 2|. Thecap 21 has a projection 29 to engage the head of the valve beingmachined to prevent twisting of the head relative to the valve stem. Onthe inside of this cap 21 is an internal shoulder 30 disposedsubstantially at right angles to the axis of rotation of the drivengear. Similarly, an internal shoulder 3| is disposed on the inside ofthe cap 28.

4 A first chuck collet 35 is disposed within the housing and has asurface 36 to engage the internal shoulder 38 of the cap 21 which isthreaded into the bearing portion 20. A second chuck collet 31 is alsodisposed within the housing and has a surface 38 to engage the internalshoulder 3| of the cap 28 which is threaded into the bearing portion 2|.As is illustrated in Figure 2 of my drawings, these chuck collets 35 and31 are urged apart and against their respective internal shoulders by acollet spring 39. One of the chuck collets grips one end of the valvestem, and the other of the chuck collets grips the other end of thevalve stem, so that each end of the valve stem is chucked next adjacentthe part of the valve which is being machined and with about 2800 poundschucking pressure. I have discovered that this gripping of both ends ofthe valve stem prevents twisting and deformation of the metallicstructure of the stem.

The chuck collet 35 has a conical cam surface 40, and the chuck collet31 has a conical cam sur face 4|. A first chuck sleeve 42 is slidablycarried by the first chuck collet 35 and has a cam surface 43 tocooperate with the conical cam surface 40 of the chuck collet 35. Achuck sleeve 44 is similarly slidably carried by the'second chuck collet31 and has a cam surface 45 to cooperate with the cam surface 4| of thechuck collet 31. These chuck sleeves 42 and 44 are spaced apart with thechuck sleeve 42 having an end surface 46 and the chuck sleeve 44 havingan end surface 41 facing the end surface 46.

As is illustrated in Figures 3 and of my drawings, a plurality of balls48 may be inserted or forced between these end surfaces 46 and 41 toslide the chuck sleeves 42 and 44 apart, thus causing the chuck collets35 and 31 to grip both ends of the valve stem l8 or any other workpieceinserted therein. I have also discovered that I can control the grippingdiameter of both chuck collets by turning the cap 28 into or out of thehousing, and thereby increasin or decreasing the distance between theinternal shoulder 39 on the cap 21 and the internal shoulder 3| on thecap 28. When the distance between the shoulders is increased the spring39 will spread the chuck collets 35 and 31 further apart, and the springtension in the chuck collets 35 and 31 will cause them to expand to agreater gripping diameter.

Since the end surfaces 46 and 41 of the respective chuck sleeves arealways spaced apart and are disposed at an angle to each other, thewedging of the balls therebetween will cause the sleeves to spread apartand thereby cam the 4 chuck collets radially into the workpiece or valvestem. It is thus seen that the chuck collets 35 and 31 grip the valvestem by being radially contracted onto the valve stem. As the chuckcollets are radially contracted on the valve stem their axial spacing iscontrolled by the internal shoulders 30 and 3| so that the chuck colletswill not tend to lengthen the valve stem.

I have provided the cap 28 with a lock screw 49, and the end of thebearing portion 2| with a plurality of recesses 50 which cooperate withthe head of the lock screw 49 to lock the cap 28 into the bearingportion 2| after it has been threadably turned into the housing thecorrect distance to provide the desired spacing between the internalshoulders 30 and 3|.

In Figures 2 and 3 of my drawings I best illustrate a spool which I haveslidably inserted in the housing or driving gear II. This spool 5| hasan internal cam surface 52 which engages the balls 48 to force thembetween the end surfaces 46 and 41 of the chuck sleeves 42 and 44. Thespool 5| is slidably mounted about the chuck sleeves and slides axiallyof the driven gear. The cam surface 52 is of larger radius on one end ofthe spool 5| than on the other end, so that when the spool 5| is slid tothe open position as illustrated in Figure 2 the balls 48 are not forcedbetween'the chuck sleeves 42 and 44. However, when the spool 5| is slidto the closed position as illustrated in Figure 3, the cam surface 52forces the balls 48 between the chuck sleeves 42 and 44, thus causingthe chuck collets to grip the valve stem inserted therein. Since thespool 5| is entirely enclosed within the driven gear I l I have provideda drive pin 53 carried by the cap 21 and a drive pin 54 carried by thecap 28, to enable me to slide the spool back and forth. Since the pin 53has a length equal to the thickness of the cap 21, I have provided thecap with a recess 55 so that the pin 53 may be reciprocated withoutstopping the machine. The pin is always located within the outer surfaceof the cap 21 and thus will not become damaged by the tool I4.

I have discovered that just a few hundred pounds of pressure on thesedrive pins 53 and 54 will cause a gripping pressure of approximately2800 pounds on the workpiece being chucked and machined. It isunderstood that when I refer to these gripping pressures I am referringto the pressures which I found in the machine which I have constructedfor machining valves. However, it is understood that chucking mechanismsof various sizes may be constructed, and that these chucking mechanismswill produce many dif ferent gripping pressures on the workpiece.

Although my invention has been described with a certain degree ofparticularity in its preferred form, it is understood that the presentdisclosure of the preferred form has been made only by way of exampleand that numerous changes in the details of construction and thecombination and arrangement of parts may be resorted to withoutdeparting from the spirit and the scope of the invention as hereinafterclaimed.

What is claimed is:

1. In a chucking mechanism for a workpiece, a housing having a firstinternal shoulder on one end thereof, a cap carried by the other end ofsaid housing and having a second internal shoulder spaced from the saidfirst internal shoulder, a first chuck collet within said housing andabutting said first internal shoulder, a second chuck collet within saidhousing and abutting said secgames ond internalish'oulder,"eachofsa'TdF'chuck collets having a cam surface, a first chuck sleeveegagingthecam surface of the first chuck'collet, asecondfchuclksieeveifigagmg the cam surface of the second :ch'uckcolletaridlspacedfiqom the first chuck sleeve, ball meansfw'ithinthefho' "ifig and insertable between the chuck sleeves remove the sameapart to cause the chuck collets togrip their respective ends'oftheworkpiece, a spool shiftable in the housing-and cammed t fQrce theball means betweenthe chucksleeve afirst pin; slidably carried by said-l ousing and; ;engaging one end of the spo01.;to-shi-ft the-spool inone direction, and, a second,pingcarriedyby.the cap and engaging theopposite end of the spool to shift the same in the opposite direction.

2.A rotatable chucking device for rotating a workpiece for machiningboth ends thereof at the same time, said device comprising, a gearhaving opposite surfaces with a central cylindrical aperture extendingtherebetween, a cap on each side of said gear and thus in each end ofsaid aperture, a pair of opposed chuck collets within said aperture andbetween said caps, each having an external, somewhat conical-shapedsurface, chuck sleeves slidable on said collets and having opposedtapered end surfaces, said chuck sleeves having internal taperedsurfaces engaging the somewhat conical-shaped surfaces of the chuckcollets to radially contract the same onto a workpiece inserted therein,one cylindrical spool shiftable in the aperture of said gear andsurrounding both of said chuck sleeves, said spool having a cam recessof variable depth on the inside thereof, wedge means in said recesswithin said spool and between the opposed tapered end surfaces of thechuck sleeves, and means extending outwardly through said caps forshifting said spool and thereby camming said wedge means between thechuck sleeves to radially contract the chuck collets.

3. A rotatable chucking device for rotating a workpiece for machiningboth ends thereof at the same time, said device comprising, a gearhaving opposite surfaces with a central cylindrical aperture extendingtherebetween, a cap on each side of said gear and thus in each end ofsaid aperture, a pair of opposed chuck collets within said aperture andbetween said caps, each having an external, somewhat conical-shapedsurface, chuck sleeves slidable on said collets and having opposedtapered end surfaces, said chuck sleeves having internal taperedsurfaces engaging the somewhat conical-shaped surfaces of the chuckcollets to radially contract the same onto a workpiece inserted therein,one cylindrical spool shiftable in the aperture of said gear andsurrounding both of said chuck sleeves, said spool having a cam recessof variable depth on the inside thereof, a plurality of balls in saidrecess within said spool and between the opposed tapered end surfaces ofthe chuck sleeves, and means extending outwardly through said caps forshifting said spool and thereby camming said plurality of balls betweenthe chuck sleeves to radially contract the chuck collets.

4. In a chucking mechanism for a workpiece, a housing having a firstinternal shoulder and a second internal shoulder spaced from the firstinternal shoulder, a first chuck collet within said housing and abuttingsaid first internal shoulder, a second chuck collet within said housingand abutting said second internal shoulder, each of said chuck colletshaving a cam surface, a first chuck sleeve engaging the cam surface ofthe first chuck collet, a second chuck sleeve engaging the 6 camsurfaceofthe second chuck collet'and'spaced from-the first chuck sleeve,fwe'dge means within the housing and. insertable between the chucksleeves to move the same apart-to cause the'chuek colletsto-grip-theirrespective ends of the workpiece. -'arspool shiftable inthe housing and cammed; to force the wedge means between the chucksleeves, first means carriedby saidhousing; and engaging one end of-thespool to shift the spool i-n-one direction, and second meanscarriedI-b'y the housing and engaging the opposite end of the spool toshift the same in the opposite direction.

:5. A rotatable chucking device for rotating a workpiece for machining'bo'th endsthreo f atthe same time, said device comprising, a supportingmember having opposite surfaces with an aperture extending therebetween,a cap member on each side of said supporting member and thus in each endof said aperture, a pair of opposed chuck collets within said apertureand between said cap members, each having an external cam surface, chucksleeves slidable on said collets and having opposed tapered endsurfaces, said chuck sleeves having internal cam surfaces engaging theexternal cam surfaces of the chuck collets to radially contract the sameonto a workpiece inserted therein, one spool shiftable in the apertureof said supporting member and surrounding both of said chuck sleeves,said spool having cam recess means of variable depth on the insidethereof, wedge means in said recess means within said spool and betweenthe opposed tapered end surfaces of the chuck sleeves, and spoolshifting means extending outwardly through at least one of said membersfor shifting said spool and there-,

by camming said wedge means between the chuck sleeves to radiallycontract the chuck collets.

6. In a chucking mechanism for a workpiece, a housing having a firstinternal shoulder and a second internal shoulder spaced from the firstinternal shoulder, a first chuck collet within said housing and abuttingsaid first internal shoulder, a second chuck collet within said housingand abutting said second internal shoulder, each of said chuck colletshaving a cam surface, a first chuck sleeve engaging the cam surface ofthe first chuck collet, a second chuck sleeve engaging the cam surfaceof the second chuck collet and spaced from the first chuck sleeve, wedgemeans within the housing and insertable between the chuck sleeves tomove the same apart to cause the chuck collets to grip their respectiveends of the workpiece, a spool shiftable in the housing and cammed toforce the wedge means between the chuck sleeves, and spool shiftingmeans extending outwardly through said housing for shifting said spooland thereby camming said wedge means between the chuck sleeves toradially contract the chuck collets.

7. A rotatable chucking device for rotating a workpiece for machiningboth ends thereof at the same time, said device comprising, a supportingmember having opposite surfaces with an aperture extending therebetween,a cap member on each side of said supporting member and thus in each endof said aperture, a pair of opposed -chuck collets within said apertureand between said cap members, each having an external tapered surface,chuck sleeves slidable on said collets and having opposed tapered endsurfaces, said chuck sleeves having internal tapered surfaces engagingthe external tapered surfaces of the chuck collets to radially contractthe same onto a workpiece inserted therein, one spool shiftable in theamp.

ture of said supporting member and surrounding both of said chucksleeves, said spool having cam reoess means of variable depth on theinside "thereof, wedge means in said recess means within said spool andbetween the opposed tapered end surfaces of the chuck sleeves, and spoolshifting means extending outwardly through at least one of said membersfor shifting said spool and thereby camming said wedge means between thechuck sleeves to radially contract the chuck colletsi ALFRED E.DRISSNER.

REFERENCES CITED The following references are of record in.the fileofthis patent:

UNITED STATES PATENTS Number 10 Number Name Date Ennis July 16, 1918Bartlett et al. Jan. 3, 1922' Pannwitz Dec. 31, 1929 Avilla Feb. 18,1930 Lovely Mar. 27, 1945 FOREIGN PATENTS Country Date Switzerland of1921 Germany of 1906 Switzerland of 1940 Germany of 1926

